Introduce an asynchronous version of run_on_cpu() i.e. the caller
doesn't have to block till the call back routine finishes execution
on the target vcpu.
Signed-off-by: NChegu Vinod <chegu_vinod@hp.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJuan Quintela <quintela@redhat.com>